Process of manufacture of absolute alcohol



Jan. 21, 1930. RICARD 1,744,504

PROCESS OF MANUFACTURE OF ABSOLUTE ALCOHOL Filed July 1924 3 Sheets-Sheet l AZEOTEOfl/C MIXTURE I ll A Ql/EOl/S A L COHOL 0 v ALCOHOL, fNTEAN/NG BODY fA LITTLE WATEE J A ALCOHOL [WTEANl/VG 500) M m V ALCOHOL, ENTEAN/A/O 500 Y 2 9: GEE/1T AMOu/VT 0F WA TEE 335132: P ABSOLUTE :4 ALCOHOL Jan. 21, 1930.

E. RICARD PROCESS OF MANUFACTURE OF ABSOLUTE ALCOHOL Filed July 3 1924' 5 Sheets-Sheet 2 4L COHOL, ENTEA/N/NG ear 4 urn:- WA 1-5/2 ALCOHOL 56V TRAIN/1V6 5 00 J AMOUNT OF WATEE 4250 T8 OP/C M/XTUEE mamas ALCOHOL ALCOHOL ABSOL UTE A LCOHOL Jan. 21, 1930. E. RICARD PROCESS OF MANUFACTURE OF ABSOLUTE ALCOHOL 5 Sheets-Sheet 3 flZfOTEOP/C MIXTURE P325 33 7 3 1 :55: L EELS;

a wee Filed July 3; 1924 AZfOTEOP/C M/XTZ/EE ALCOHOL f f/VTEA/Nl/VG 500 Y 45504 u r: "Taco/10L A Ql/EOUJ ALCOHOL Patented Jan. 21, 1930 UNITED STATES PATENT OFFICE ELOI RICABI), 0F MELLE, FRANCE, ASSIGNOR, BY MESNE' ASSIGNMENTS, TO U. S. IN- DUSTRIAL ALCOHOL 00., OF NEW YORK, N. Y A CORPORATION OF WEST VIRGINIA PROCESS OF MANUFACTURE OF ABSOLUTE ALCOHOL Application filed July 3, 1924, Serial No. 724,132, and in Belgium July 6, 1923.

The present invention relates to improvements in the process for the manufacture of absolute alcohol by the addition of a substance termed entraining body, which will form with water a ternary azeotropic mixture having the minimum boiling point. It is known that. when there is added to the commercial alcohol. to be dehydrated, a body of this kind capable of forming a ternary azeotropic mixture and when this mixture is distilled, the vapors resulting from the distillation will contain the three components of the azeotropic mixture in a constant ratio irrespectiveof the quantities of the bodies in the reaction which were originally placed in the distilling column. In these conditions, the water can be entirely withdrawn from the mixture, and the column then contains only a binary mixture consisting of absolute alcohol and the entraining body, which mixture is separated by continuing the distillation so that absolute alcohol is finally ob tained at the bottom of the column.

' It has further been proposed to treat the vapors of the azeotropicmixture which are discharged from the distilling column, and to produce, after condensation, either homogeneous liquid or a. liquid which separates into two layers, in order to recover the entraining body and the absolute alcohol contained in the homogeneous liquid or in the liquid consisting of two layers.

The present invention relates to an improvement in the process described in my application Serial No. 688,049, filed January 23, 1924, which consists in the utilization as the entraining liquid of a mixture of liquids'which are suitably selected for the purpose, so as to take advantage of the favourable properties of one or moreof the said liquids and to eliminate their unfavourable properties, so that on the whole the opera tion may be carried out with greater facility,

or the output of the same may be increased.

The application Serial No. 688,049, discloses in general a process for producing absolute alcohol from aqueous alcohol by the addition of an entraining liquid, such, for example, as a petroleum hydrocarbon, the'distillation being carried out therewith so as toobtain a condensate which separates into liquid layers, the layer containing the high percentage of entraining liquid being returned to the still,

while the layer containing the high percentage of Water is first subjected to the action of a dehydrating substance and then returned tmthe still.

More specifically, the subjectmatter of my said application, Serial No. 688,049, may be Example I In this example the withdrawing body consists of butyl chloride.

In the distilling column A, Fig. 1,1'intro- A duce a quantity of butyl chloride. I then introduce the commercial alcohol to be dehydrated (in the state of liquid or vapor) through the tube B; The withdrawing body and alcohol are introduced vpreferably in quantities suchthat the withdrawing body and the water of the alcohol have the ratio given hereinafter in the azeotropic mixture, the alcohol being present ina greater percentage than given in the azeotropic mixture, however. The withdrawing body can also be present in a somewhat greater ratio.

The column is heated by means of the worm tube C. The vapor mixture of azeotropic nature is discharged through the conduit D at 63 C. and it has substantially the following percentage composition by volume:

Butyl chloride--. 76.7 I Alcohol 18.5 Water 4.8

The said mixture is condensed in the re- -butyl chloride and alcohol is ,frigerating condenserE and collects in the receiver F wherein it separates into two layers. The upper layer represents 87% of the azeotropic mixture and has the percentage composition by volume as follows:

Butyl chloride" Q. 87 Alcohol"-.. 11.75 Water 1.25

1 The lower layer represents 13% of the azeotropic mixture and has the percentage composition by volume as follows:

Butyl chloride", 8 Alcohol 64 Water v2 8 The upper layer is again caused to enter the column through the conduit G and is subjected to another distillation.

The lower layer proceeds through the con duit H to the dehydrating apparatus K; the dehydrating substance, which may be any of the carbonates of sodium and potassium,

sulphates of sodium, sulphates of copper, sulphates of magnesium, etc., withdraws the water in the liquid state, this being discharged through the cock M; the binar mixture of ischarged at the upper part and returns to the column through the conduit N during the distillation in the column A A A When distilled, it produces an azeotropic mixture whose boiling point is 65.7 C.

The absolute alcohol is removed as vapor or liquid at P, and is cooled in the refrigerating apparatus R.

Three regions are in fact formed in the column, i. e., the upper region A consisting of ternary mixture, the intermediate region A consisting ofbinary mixture, and the lower region A consisting of absolute alcohol, from which latter the alcohol is taken off.

Ewample ll In this example the withdrawing body consists of carbon tetrachloride.

In the distilling column A, Fig. 2, I dispose a quantity of carbon tetrachloride, I

then introduce the commercial alcohol to be centage than given in the azeotropic m'ixture, however. The withdrawing body can also be present in a somewhat greater ratio. The column is heated by the worm tube C. The vapor mixture of an azeotropic nature is discharged through the conduit D at 6l.-1

C. and'it has the following approximate percentage composition by volume:

Carbon tetrachloride 78.10 Alcohol 17.90 Water 4.00

The said mixture is condensedin the refrigerating condenser E and collects in the receiver F wherein it separates into two lay-.

ers. The upper layer represents 12.3% of the 'azeotropic mixture and has the following percentage composition by volume: a

Carbon tetrachloride 11 Alcohol Water 29 Carbon tetrachloride 87.5 Alcohol 12.0 Water 0.5

The lower layer is again caused to enter the column through the conduit Gr and is subjected to another distillation.

The upper layer proceeds through'the conduit H to the dehydrating apparatus K the dehydrating substance withdraws the water in the liquid state which is discharged through the cock M. The dehydrating substance, as above stated, may be any of the carbonates of sodium and potassium, sulphates of sodium, sulphates ofcopper, sulphates of magnesium, etc. These anhydrous salts are very hygroscopic, and may absorb the water from the liquids with which they are in contact in order to form hydrates; the hydrates themselves will "absorb additional quantities of water if the liquids being treated are sufiiciently hydrated. In the presence of liquids which are but slightly soluble in water, but are solubld in alcohol, experience shows that the anhydrous salts become hydrated and may even form aqueous solutions; it is this property that is utilized in the present process. L

The binary mixture of carbon tetrachloride and alcohol which is situated at the upper part is again brought into the column through the conduit N. When distilled, it produces an azeot-ropic-mixturewhose boiling point. is 645 C. The absolute alcohol is removed as vapor or liquid at P and is cooled in the refrigerating apparatus R.

Three regions are again formed in the colu mn,,under the same conditions as stated for'Example I. i

Example [[1 In thisv example ethyl acetate is the withdrawing bodyx In the distilling column A, Fig. 3, I dispose a quantity of ethyl acetate. I then introduce the commercial alcohol to be dehydrated (in the state of liquid or vapor) through the tube B. The withdrawing body and alcohol are introduced preferablyv in quantities such that the withdrawing body and the water of the alcohol have the ratio given hereinafter in the azeotropic mixture, the alcohol being present in a greater percentage than given in the azeotropic mixture, however. The ,withdrawing body can also be present in a somewhat greater ratio. The column is heated by the worm tube C. The vapor mixture of an azeotropic nature is discharged through the conduit D at 703 C. and has substantially the following percentage composition:

Ethyl acetate 83.2 Alcohol 9. 5 Water 7 3 mixture of ethyl acetate and alcohol is evacuated at the upper part and is again brought into the column through the conduit N. When distilled, it produces an azeotropic mixture whose boiling point is 71.8 C.

The absolute alcohol is removed as vapor or liquid at P and is cooled in the refrigerating apparatus R.

Three regions are formed in the column, as stated in the case of Example I.

My present invention is an improvement over the invention just described in connection with my application Ser. No. 688,049, and is set forth in the following examples Example I .Benzene when used alone as the entraining body will produce a ternary mixture having the minimum boiling point (about C.) and which separates by condensation into two layers. The bottom layer, which contains the major part of the water in the mixture, represents 16% of the total volume and contains some 32% of water, thus afiording, per 100 volumes of distillate, a withdrawal of 5,12 volumes of water. The upper layer would have the following composition by volume: benzene 85%, alcohol 13% and water 2%.

Gasoline which is well rectified so as to be entirely distilled between 100101 C. will pFoduce a ternary mixture having the minimum-boiling point C.) which separates by condensation into two layers. The bottom layer, which contains nearly all the water in the mixture, represents 37% o the total volume and contains 18% of water, afiording per 100 volumesof distillate a withdrawal of 6.6 volumes ofwater. The composition by volume of the upper layer, in this instance,

would be as follows: gasoline 96%, alcohol 3.5% and water 0.5%.

From the preceding it will be observed that aside from the advantages offered by the latent heat of vaporization and the specific heat, gasoline is more favorable than benzene as concerns the power of withdrawal of the water, but the decantation of its ternary mixture is less advantageous, since for equal amount of water withdrawn, the volume of the bottom layer to be treated will become nearly twice that of the water in'the case of benzene.

But the simultaneous use of these two entraining liquids permits one to take advantage of the favourable properties of each liquid. In the case where two entraining liquids are used together, these may be used in equal proportions by volume, although it is to be understood that these proportions may be widely varied, if desired. In fact, during the normal operation in the distilling chamber in which one distills the mixture of the three bodies, Wa ter, alcohol, and entraining body, the entraining body which consists of benzene whose ternary azeotropic mixture (water-alcohol-benzene) will boil at some 5 lower than the mixture composed of water, alcohol and gasoline, will preferably occupy the top ofthe said chamber, as well as the decantation chamber wherein it will setup a favourable decantation of a much-hydrated bottom layer. The gasoline will on the contrary tend to occupy the middle part of the distilling chamber wherein it will act with its great entraining power in order to more rapidly separate the industrial alcohol and to bring it into the upper region in which the benzene is in larger to that of benzene. This will obviously afford a greater facility in the operations, and an economy of fuel or an increased output for a given apparatus.

The invention furtherrelates to a second improvement consisting in the addition of a small quantity of water to the ternary mix-' ture whose boiling point is a minimum either to effect the decantation of the homogeneous liquid, to further a difficult decantation or to modify the composition of the bottom layer, whereby the subsequent treatment of the latter will be simplified.

Example ll.+When ethyl acetate is used as the entraining liquid, a ternary mixture is formed having a minimum boiling point and wliich is not capable of decantation. The addition of a small quantity of water causes a equal in volume to the amount of ternary mix ture produced, although these proportions may be Widely varied, as desired.

Ewample I I i .When gasoline serves as the entraining liquid, the bottom layer retains in solution a small quantity of this gasoline,

or on the order of By the addition of a very small quantity of waterbefore or after decantation of the ternary mixture supplied from the distilling chamber, we are enabled to separate nearly the Whole of the dissolved gasoline, thus simplifying the treatment. The amount of water added may, if desired, be an amount equal in volume to the amount 5 of ternary mixture produced, although these proportions may be widely varied, as desired.

What I claim is:

A process for the manufacture of absolute alcohol from aqueous alcohol, comprising the mixing together of aqueous alcohol, b'en zene and gasoline being present in sufiicient quantity to remove substantially all the water from the alcohol and the benzene'and gaso line servin as entraining bodies-to form with the alcohol an azetropic mixture containing water when distilled having a minimum boiling point, and in which the said mixture is subjected to distillation in such manner as to obtain absolute alcohol as a residue, the said gasoline having been distilled between 100 and102 C, Y

In testimony whereof I have signed this specification.

V ELOI RIOARD. 

